Move in code from netconf and docker-from-scratch

netconf/bonding.go

@@ -0,0 +1,143 @@
+package netconf
+
+import (
+	"io/ioutil"
+	"os"
+	"os/exec"
+	"strings"
+	"time"
+
+	"github.com/Sirupsen/logrus"
+	"github.com/vishvananda/netlink"
+)
+
+const (
+	base           = "/sys/class/net/"
+	bondingMasters = "/sys/class/net/bonding_masters"
+)
+
+type Bonding struct {
+	name string
+}
+
+func (b *Bonding) init() error {
+	_, err := os.Stat(bondingMasters)
+	if os.IsNotExist(err) {
+		logrus.Info("Loading bonding kernel module")
+		cmd := exec.Command("modprobe", "bonding")
+		cmd.Stderr = os.Stderr
+		cmd.Stdout = os.Stdin
+		err = cmd.Run()
+		if err != nil {
+			for i := 0; i < 30; i++ {
+				if _, err = os.Stat(bondingMasters); err == nil {
+					break
+				}
+				time.Sleep(100 * time.Millisecond)
+			}
+		}
+	}
+	_, err = os.Stat(bondingMasters)
+	return err
+}
+
+func contains(file, word string) (bool, error) {
+	words, err := ioutil.ReadFile(file)
+	if err != nil {
+		return false, err
+	}
+
+	for _, s := range strings.Split(strings.TrimSpace(string(words)), " ") {
+		if s == strings.TrimSpace(word) {
+			return true, nil
+		}
+	}
+
+	return false, nil
+}
+
+func (b *Bonding) linkDown() error {
+	link, err := netlink.LinkByName(b.name)
+	if err != nil {
+		return err
+	}
+
+	return netlink.LinkSetDown(link)
+}
+
+func (b *Bonding) ListSlaves() ([]string, error) {
+	file := base + b.name + "/bonding/slaves"
+	words, err := ioutil.ReadFile(file)
+	if err != nil {
+		return nil, err
+	}
+
+	result := []string{}
+	for _, s := range strings.Split(strings.TrimSpace(string(words)), " ") {
+		if s != "" {
+			result = append(result, s)
+		}
+	}
+	return result, nil
+}
+
+func (b *Bonding) RemoveSlave(slave string) error {
+	if ok, err := contains(base+b.name+"/bonding/slaves", slave); err != nil {
+		return err
+	} else if !ok {
+		return nil
+	}
+
+	p := base + b.name + "/bonding/slaves"
+	logrus.Infof("Removing slave %s from master %s", slave, b.name)
+	return ioutil.WriteFile(p, []byte("-"+slave), 0644)
+}
+
+func (b *Bonding) AddSlave(slave string) error {
+	if ok, err := contains(base+b.name+"/bonding/slaves", slave); err != nil {
+		return err
+	} else if ok {
+		return nil
+	}
+
+	p := base + b.name + "/bonding/slaves"
+	logrus.Infof("Adding slave %s to master %s", slave, b.name)
+	return ioutil.WriteFile(p, []byte("+"+slave), 0644)
+}
+
+func (b *Bonding) Opt(key, value string) error {
+	if key == "mode" {
+		// Don't care about errors here
+		b.linkDown()
+		slaves, _ := b.ListSlaves()
+		for _, slave := range slaves {
+			b.RemoveSlave(slave)
+		}
+	}
+
+	p := base + b.name + "/bonding/" + key
+	if err := ioutil.WriteFile(p, []byte(value), 0644); err != nil {
+		logrus.Errorf("Failed to set %s=%s on %s: %v", key, value, b.name, err)
+		return err
+	} else {
+		logrus.Infof("Set %s=%s on %s", key, value, b.name)
+	}
+
+	return nil
+}
+
+func Bond(name string) (*Bonding, error) {
+	b := &Bonding{name: name}
+	if err := b.init(); err != nil {
+		return nil, err
+	}
+
+	if ok, err := contains(bondingMasters, name); err != nil {
+		return nil, err
+	} else if ok {
+		return b, nil
+	}
+
+	logrus.Infof("Creating bond %s", name)
+	return b, ioutil.WriteFile(bondingMasters, []byte("+"+name), 0644)
+}